Thursday 26 March 2015

Waders at Lake Corangamite - Colac


Lake Corangamite is a large hypersaline lake located north west of Colac in the Lakes and Craters region of the Victorian Volcanic Plains. A number of the lakes in the region are important wader sites listed under the Ramsar Convention Ramsar-listed Western District Lakes. The last volcanic activity in the area was about 4,500 years ago, which for Australia is relatively recent. The lake was formed when larva flow blocked the local catchment drainage outlet.
Lake Corangamite is large with a shoreline length of about 150 kms and an area of 230 square kms (mean depth is about 5 m). Surprisingly for such a large lake there is only one public access point located a short distance from the small town of Alvie and the Red Rock scenic lookout, which provides an excellent view of the area including the lake. In hindsight it is a great shame that our forebears did not see any value in preserving some of the volcanic plains vegetation around Lake Corangamite.
We visited the lake to see if there were any waders present and were not disappointed as there were thousands of Red-necked Stints and good numbers of Curlew Sandpipers feeding together along the shoreline at the public access point. It was a moving scene to watch, knowing these small shorebirds were feeding actively to fuel up for their immanent migration flight to the arctic tundra to breed there during the short northern summer.
An added bonus was to see a few birds in breeding plumage as we mostly only see birds in their somber non-breeding plumage during their summer visit to Australia.
Curlew Sandpiper in breeding plumage.
Along the section of shoreline we visited I estimated there were around 500 Red-necked Stints over a distance of about 1km. Assuming this small area of public access was not, by some freak of nature and extremely long odds, the only shoreline favoured by the Stints then the numbers around the lake could be large. If two thirds of the shoreline, that is 100 kms, had Stints in the same numbers as the public access section then there could be 100 x 500 = 50,000 Red-necked Stints on Lake Corangamite. The total Australian summer population estimate is 270,000 birds so 50,000 may not be an unrealistic estimate.  
The Curlew Sandpipers were in much smaller numbers. My Shorebirds of Australia (Geering, Agnew and Harding) reprinted in 2008, put the Australian estimate for Curlew Sandpipers at 118,000.  Their numbers have crashed since 2008 due to the destruction of tidal flats for land reclamation in Korea, which was a critical refueling stop on their migration flyway.
Looking carefully through the birds near my observation point I could not see any other wader species. No doubt many other water birds and shorebirds (waders) use this lake at times. I have read that Banded Stilts once bred on the lake back when their breeding locations were a mystery.
Approaching the shoreline of Lake Corangamite where hundreds of waders were feeding.
It is impossible to capture the extent of birds feeding along the shore, this is just a very small section. There are 41 birds in the photo.
The Curlew Sandpipers and the much smaller Red-necked Stints fed together.
The Curlew Sandpiper is surrounded by Stints.
Curlew Sandpiper, non breeding, Stint behind.
Curlew Sandpiper with the start of some breeding plumage.
Curlew Sandpiper in breeding plumage.
Red-necked Stint non breeding plumage.
Two Red-necked Stints with bird on left showing some red on neck.
This bird has more red on neck making the common name for this species obvious.
If you are ever in the Colac area, especially during the summer migrant wader season, a visit to Lake Corangamite and Red Rock lookout is recommended (go to the Visitor Information Centre in Colac for directions if you are unsure how to find the public access point). 

2 comments:

  1. Apparently there can also be Brolgas there at times. Great to see so many shorebirds, with some colouring up. There were also a few on the shore of Lake Colac the other day when I stopped for a short time, but they were unfortunately being disturbed by a walker with a dog off leash.

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  2. Might have to visit Colac next time we are in Melbourne.

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